Add QScriptString::toArrayIndex() function

Avoid hacking a custom toArrayIndex() in the example; instead provide
an ECMA-compliant conversion that's as fast as possible (having to
convert the QScriptString to a QString and then convert the result to
a number is considerably slower than calling JSC's
Identifier::toArrayIndex() function directly).

Reviewed-by: Olivier Goffart

2 files changed, 31 insertions, 0 deletions

diff --git a/src/script/api/qscriptstring.cpp b/src/script/api/qscriptstring.cpp
index 1ede51c..10fccd0 100644
--- a/src/script/api/qscriptstring.cpp
+++ b/src/script/api/qscriptstring.cpp
@@ -68,6 +68,10 @@ QT_BEGIN_NAMESPACE
 
   Call the toString() function to obtain the string that a
   QScriptString represents.
+
+  Call the toArrayIndex() function to convert a QScriptString to an
+  array index. This is useful when using QScriptClass to implement
+  array-like objects.
 */
 
 /*!
@@ -164,6 +168,31 @@ bool QScriptString::operator!=(const QScriptString &other) const
 }
 
 /*!
+  \since 4.6
+
+  Attempts to convert this QScriptString to a QtScript array index,
+  and returns the result.
+
+  If a conversion error occurs, *\a{ok} is set to false; otherwise
+  *\a{ok} is set to true.
+*/
+quint32 QScriptString::toArrayIndex(bool *ok) const
+{
+    Q_D(const QScriptString);
+    if (!d) {
+        if (ok)
+            *ok = false;
+        return -1;
+    }
+    bool tmp;
+    bool *okok = ok ? ok : &tmp;
+    quint32 result = d->identifier.toArrayIndex(okok);
+    if (!*okok)
+        result = -1;
+    return result;
+}
+
+/*!
   Returns the string that this QScriptString represents, or a
   null string if this QScriptString is not valid.
 
diff --git a/src/script/api/qscriptstring.h b/src/script/api/qscriptstring.h
index 40d156c..bf5d1d5 100644
--- a/src/script/api/qscriptstring.h
+++ b/src/script/api/qscriptstring.h
@@ -67,6 +67,8 @@ public:
     bool operator==(const QScriptString &other) const;
     bool operator!=(const QScriptString &other) const;
 
+    quint32 toArrayIndex(bool *ok = 0) const;
+
     QString toString() const;
     operator QString() const;